One definition of "far away" in this context is:
These values define the so-called inner fences, beyond which an observation would be labeled a mild outlier.
Extreme outliers are observations that are beyond the outer fences:
Outliers usually demand special attention since they may indicate problems in sampling or data collection or transcription. Alternatively, an outlier could be the result of, for example, a truly unusual response to a given treatment, calling for further investigation by the researcher.
See also: box plot